Liquid carton and seal therefor



Aug. 13, 1957 R. BOYD LIQUID CARTON AND SEAL THEREFOR Filed June 9, 1952IN VEN TOR.

' 2066/21. fiq BY w g 2,802,613 LIQUID CARTON AND SEAL THEREFOR RobertLeo Boyd, La Grange Park, Ill., assignor, by mesne assignments, toAmerican Can Company, New York, N. Y., a corporation of New JerseyApplication June 9, 1952, Serial No. 292,538 7 Claims. (Cl. 229-7) Thisinvention is related to those disclosed in the applications of LeRoyStaunton, Serial Nos. 270,575, now abandoned, and 270,576, and Ervin B.Kodat, Serial No. 270,603, now Patent No. 2,754,045 all of which werefiled on February 8, 1952, covering paper liquid containers and sealstherefor.

The present invention, as in the case of those disclosed in theapplications above identified, relates to cartons such as are commonlyused for the distribution of milk, and is characterized by a cornerpouring opening disposed adjacent the top in the side walls thereof,which opening is sealed until it is desired to open the carton.

The present invention differs from those disclosed in the aforesaidapplications in that a seal is provided which is made of one or morerelatively thin membranes of cellulose material impregnated With athermosetting resin, which is sealed by heat and pressure in overlyingrelation to the pouring opening in such a way as to become permanentlyafiixed to the contiguous areas of the side walls of the carton.

The present invention shares the idea of having a permanent closuresealed in permanent engagement with the upper edge of the side walls ofthe carton body, but difiers from the latter in that the pouring openingis sealed by an imperforate and relatively unweakened membrane, ormembranes, which must be ruptured by a lifting force applied to thecorner of the carton at which the pouring incision is provided. Thecorner of the top, together with the portion of the side walls afiixedthereto which lie above the pouring opening, are thus forced upwardly asthe seal is destroyed.

it is among the objects of the present invention to provide a seal forcartons of the class described in which the pouring incision and an areasurrounding the latter on the outside of the carton are protected by anoverlying seal, which prevents the lip of the pouring opening frombecoming soiled and prevents the ingress of contaminating foreignmatter.

It is another object of the invention to provide a seal interiorly ofthe carton which surrounds the pouring incision in a way effectively toexclude the liquid contents from gaining access thereto, thus topreclude the liquid from entering the cut edges defining the pouringopening, which, in the case of cardboard, is a wicking material capableof inducing liquid to flow through the walls of the carton in directionsparallel to the surfaces thereof by capillary action. This isobjectionable, since the liquid thus entrained into the walls softensthe latter and causes them to weaken structurally, with the possibilityof incurring failure of the carton.

The present invention, like those hereinbefore identified, ischaracterized by a corner pouring carton, the pouring edge of which isfree from obstructing rings or dams such a might prevent the completedischarge of the contents of the carton, to the end that residualamounts of the contents usually wasted are saved and used.

It is a further object of the present invention to provide a carton thatis completely sealed by permanent ice closures at the top, bottom, andpouring incision, until it is desired to void the contents thereof. Animproved method for making such a carton is also contemplated.

Other objects and advantages will become apparent hereinafter when thefollowing description is considered in conjunction with the accompanyingdrawings, in which- Figures 1 to 4, inclusive, are fragmentary sectionalelevations taken through the side wall and adjacent top of a cartonembodying this invention, at the pouring incision therein; and V Figures5 and 6 are isometric views of a carton embodying the present inventionas shown in the preceding figures.

In the drawings, the body portion 10 of the carton is formed ofcellulose material, such as cardboard, which is laminated to requisitestrength, and impregnated with a thermosetting resin that is non-toxic,and impervious to liquid. A bottom member 12 is suitably formed andsealed to the edges of the body portion 10. A top member 14 of materialsimilar to that constituting the body portion 10 is formed with aninverted U-shaped channeled marginal portion 16 which is adapted to beinverted upon the upper edges 18 of the carton body and permanentlysealed thereto, preferably by thermosetting resinous adhesive. This lastoperation is usually undertaken by the persons concerned with fillingthe carton, such as dairymen, who install the top closures and heat sealthem in permanent engagement with the upper edges of the carton bodyafter the milk or other liquid contents have been introduced therein.

The side walls 10 of the carton are incised as at 20 completely throughthe thickness of the material, so as to span a corner of the carton asbest appears in Figures 5 and 6. The pouring incision 20 is locatedadjacent the top, but sufficiently below the flange 16 thereof so as tobe unobstructed by the latter prior to being opened.

Seals of tissue-like membrane 22 and 24 are applied, which are of aweight corresponding to second-sheet tissues commonly used in makingcarbons of typewritten texts. These tissues are impregnated with athermosetting adhesive, which is preferably the same as that with whichthe carton side walls 10 and closures 12 and 14 are impregnated. Thetissues are of a size to overlie the pouring incision 20 so as toeifectively seal the latter while extending in engagement with theadjacent areas of the carton side walls over a substantially greaterarea than that defining the length of the incision itself.

As shown in Figures 1 and 2, the tissues membranes 22 and 24 are sealedinside and outside of the carton so as to extend from a point below thepouring incision 20 in overlying relation to the latter to a pointbeneath the closure flanges 16.

As shown in Figure 3, only the internal membrane 22 need be applied,while in Figure 4 only the external membrane 20 is contemplated. Each isin sealing relation to the pouring incision 20 in a manner correspondingto that disclosed in the preceding figures.

In manufacturing the carton of the present invention, it is desirable toprovide a carton wall 10 that is cut so as to provide a smallercross-sectional area at the bottom of the carton body than at its topwhen wrapped or folded, so that the latter may be stacked one withinanother for shipment prior to filling. The pouring incision 20 is cutcompletely through the wall blank prior to its formation and is locatedso as to span a corner of the carton body after it is formed on amandrel. The body blank is impregnated with resin and the internaltissuelike membrane 22, also impregnated, is applied and sealed inoverlying relation to the incision 20. The carton body is then wrappedon a mandrel in such a way that the already applied seal 22 is disposedagainst the mandrel so as to be inside the carton. The purpose for thisis that v 3 the internal seal; when first applied and later wrapped, issubject'only to compression, while if the outer seal 24 were to beapplied before wrapping on the mandrel, it would be subjected to suchconsiderable, tension upon wrapping as; mi'ght'cauisel itsfailureig 3Therefore," it is"desirable,' and 'accor'dancejfwith the practices" of jthe present invention; to. applyfthe internal in Figure 4, it isnevertheless to have such'membranes both'inside and outsldeas sealf'with"thefca'rton ibody in its" blank' forrn, and .thereafter"to'w'ra'pfthelatter and ?to seal the 'overlappingedg'es of"the"'carton"body' in the usual" way' by application of." heat andpressure thereto, so as to cause the thermos'etting IesinWitliWhichthe'body' is impregnated to adhere at fthe interfac'efof theoyerlappedpertions and to become cu'redin'this position;

An outer seal 24 of tissue-like material impregnated with attrermesezang. plasticas previously described is thefiappliedfin'overlying relationto the incision 20, and the" bottom .tlien prefefablyis also applied to the carton body; and b'o'thoflthesefare' sealeddntoposition at the same'ftime. The "carton is thedairyor tothe ultimateus'er for filling, after which theftopcl'osur'esMare disposed inoverlying relation to the upper edges ofthe cartonbody, including theportions 18and those'areas of'the sealing tissues 22 and 24 whichproject beneath the flanges All of these parts arethensealedper'manently' together by heat and pressure.

As appears'in Figure 6, to open a carton sealed in this manner, it ispreferably disposed on a steady surface, such as a table, and grasped bythe hands so that the fingersconfin'e it and steady it against thetable. Then, with thethumbs positionedupon a rim of the topadjacentth'ep'ourin'g opening 20, an upward pressure is exerted so as tocause the sealing'membranes 22 and 24 to rupture to permit the pouringincision 20 'tobe opened by a hinge action along the corner of the top,which carrieswithit'thefpermanently attached rim portion 13 definingthe-upper edge. of the carton body that overlies the pouringincision'20'. The carton in open position is shown in Figures 2 "and 6.

In the applications identified in the first paragraph of A thisspecification, the seals were either of relatively heavy stock weakenedby'perforations in one way or another to afford removal, or else were ofpressure sensitive adhesive'material which could 'be removed from thepouring incision substantially intact.

Iii-the present case, seals of sufiicient thinness to be frangible'arepermanently sealed into position over the pouring'incision and aredestroyed along the line of the latterupon application of suitablepressure at the time it is'desir'ed to void'the contents ofthe carton.The seal of the present invention is'stronger than the sealsheretofore'contemplated and has the advantage of maintainingthe'contents oftlie cartons inviolate until the seals are brokenbeyond'any' chance of disguising the fact. The seal'bei'ng a permanentone, access to the contents is permitted only, by its destruction, whichdiffers from all known'carton seals on the, commercial market today.

In certain of 'the latter, non-wicking material, such as aluminum'foil,is applied to prevent too firm adherence between the portions of the topand the rim of the carton U body, so that the top may be separatedtherefrom without becoming unduly mutilated. These proposals areobjectionable, in thatthe non-wicking material provides an imperfectseal, which, by its very nature, it is intended to do.

The present invention, however, provides a permanent seal, both wherethe top and bottom closures join the adjacent rim ofthe carton body andat the pouring incision, so that a completely hermetically sealedcontainer is provided until the seal isbroken'as above described.

Although it is within the purview of the present invention to provideone sealing membrane either within the carton as shown in Figure 3, oroutside thereof as shown "then'ready tobe shipped to 0 ,as mightaccidently. shear the preferred embodiment appears in Figures 1 and 2,for the reasons already set forth herein first above. As so applied,each seal reinforces the other and tends to maintain the continuity ofthe wall surfaces inside and outside the carton effectively to resistlateral displacement between the cut edges, such anyv one of the sealsin. two prematurely."

I claim? 1. A method of making. cartons forcontaining and dispensingliquid and'the lik6,-Wl1l'l1 includes-impregnating a blank of relativelyheavycellulose material with a liquid'proof, thermosetting'resin,incising apouring opening in said blank, impregnatingablank ofrelatively light cellulose material with a thermosetting adhesive havinan aflinity for said resin so as to bond therewith when heated, applyingapatchof said latter-blankto-the area immediately surrounding saidpouring openingtherein by heat and pressure'to seal said heavy blank to'close 'sai'dopening, winding said heavy blank upon'a formingm'andrel' toform ajtube with said patch inside said tube, and thereafter heatsealing atleast one end closure in said tube.

2. The'method of claiml'furtherincluding applying I a secondpatch" fromsaidlight blank externally of said' tube after the latter'is wound, andheat sealing said second patch. to the walls offsaidtube surroundingsaid pouring openingjpe'rmanentlyrto close the same until ruptured. 1

3. A liquid dispensing carton having a polyhedral tubular body,permanently attached toth'e ends ofsaid body. to close the same, alinearpouring incision spanning a cornerof said body andextendi'ngfor alimited'di'stance along contiguous portions'of the included side wallsandpenetrating the latter, said incision extending'subs'tantiallyparallel to the top edges of said tubular body and approximately in theplane of the lower face of said top closure and below the flangethereof, a frangible membrane of thinner material than said bodydisposed inlclosing relation to said incision for being ruptured when.pressure is applied to said top closure adjacent said incision, saidmembrane having been treated with a thermosetting adhesive and beingpermanently secured to the side walls of said body circum acent to saidincision to seal the same until ruptured.

4. The invention ofclaim 3, in which the membrane described is appliedboth internally and externally of the carton body.

5. The inventionof is disposed internally of the carton body.

6; The invention of claim 3, in which said membrane is disposedexternally ofsaid carton-body.

7. The invention of claim 3, in which said carton body stock isimpregnated with a thermosetting resin to which said adhesive bonds whenheated in contact therewith.

References Cited in the file of this patent UNITED STATES PATENTS1,262,992 Stephano Apr. 16, 1918 1,541,143 Hoile June 9, 1925 1,719,923Cochran July 9, 1929 2,027,747 Morton Jan. 14, 1936 2,302,083 WilcoxNov. 17, 1942 2,341,379 Householder et a1. Feb. 8, 1944 2,362,862Sidebotham Nov. 14, 1944 2,398,405 Brooks Apr. 16, 1946 2,460,820Hogapian Feb. 8, 1949 2,608,341 Eckman Aug. 26, 1952 FOREIGN PATENTS426,341 GreatBritain Mar; 29. 1935 Y the patch permanently to flangedcountersunk top'a'nd bottom closures.

claim 3, inwhich said membrane

